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Category: Ecological Research

Title: Fire history and stand structure of two ponderosa pine-mixed conifer sites: San Francisco Peaks, Arizona, USA

Author: * Heinlein, T.A. , Moore, M.M. , * Fule, P.Z. , * Covington, W.W.

Subject: Age structure, Aspen, Douglas Fir, Fire effects, Fire scars, White fir

Abstract: We reconstructed historical fire regimes and contemporary and historical stand structures in two stands of ponerosa pine-mixed conifer forests on the San Francisco Peaks in northern Arizona, USA. Thirty-four fire-scarred specimens recorded 256 fires from the EAST and WEST study site. Fires were recorded between 1739 and 1903 for the EAST site and between 1548 and 1947 for the WEST site. The mean fire return interval (MFI: 25(percent) scarred) for the period 1690-1892 was 10 years with a range of 3-21 years for the EAST site. The WEST site MFI (period 1612-1876) was 9 years with a range of 3-21 years. Seasonal patterns of fire occurrence showed that the majority of fires burned during the summer months. Fire interval (years) means, variances and distributions between the EAST and WEST sites were not statistically different from one another for the common analysis period of 1690-1876. Historically, both the EAST and WEST sites were dominated by ponderosa pine, with scattered individuals of Douglas-fir, limber pine and white fire, with tree densities that ranged from 43 to 60 trees per hectare (TPH). Current forest composition has shifted from fire-tolerant ponderosa pine to less fire-tolerant, more shade-tolerant species, with tree densities ranging from 928 to over 1700 TPH. We suggest that the dramatic structural changes recorded at our study sites occurred since fire regime disruption.

Date: 2005

Type: Journal

Source: International Journal of Wildland Fire

Identifier: 14(3):307-320

Publisher: CSIRO, http://www.publish.csiro.au/?nid=114

Format: PDF

Language: English